Protein interaction network analysis of mTOR signaling reveals modular organization.
Protein interaction network analysis of mTOR signaling reveals modular organization.
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DOI：
10.1016/j.jbc.2023.105271
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发表时间：
2023-11
影响因子：
4.8
通讯作者：
Smith, Stephen E P
中科院分区：
文献类型：
--
作者：
Wehle, Devin T;Bass, Carter S;Sulc, Josef;Mirzaa, Ghayda;Smith, Stephen E P
哺乳动物雷帕霉素靶蛋白（mTOR）是一种丝氨酸-苏氨酸激酶，其作为翻译的中心介体，在细胞生长、突触可塑性、癌症和广泛的发育障碍中起重要作用。连接脂质激酶（磷酸肌醇3-激酶）、蛋白激酶（AKT）和翻译起始复合物（EIF）与mTOR的信号级联反应已被广泛建模，但未完全描述mTOR系统行为。在这里，我们使用定量多重免疫共沉淀监测蛋白质相互作用网络（PIN）组成的mTOR相关蛋白质之间的300+二元相互作用。使用一个简单的模型系统的血清剥夺或新鲜培养基喂养的小鼠3 T3成纤维细胞，我们观察到广泛的PIN重塑涉及27+个别蛋白质相互作用后1小时，尽管磷酸化的变化后，观察到只有5分钟。使用磷酸肌醇3-激酶、AKT、mTOR、MEK和ERK的小分子抑制剂，我们定义了PIN的子集，称为“模块”，其对每种抑制剂的反应不同。使用来自患有由致病性PIK 3CA或MTOR变体引起的过度生长障碍的个体的原代成纤维细胞，我们发现mTOR通路组分的过度活化反映在过度活化的PIN中。我们的数据定义了mTOR PIN的“模块化”组织，其中协调的相互作用组响应于不同节点的激活或抑制，并证明激酶抑制剂以复杂的方式影响模块化网络架构，与信号转导的简单线性模型不一致。
The mammalian target of rapamycin (mTOR) is a serine-threonine kinase that acts as a central mediator of translation and plays important roles in cell growth, synaptic plasticity, cancer, and a wide range of developmental disorders. The signaling cascade linking lipid kinases (phosphoinositide 3-kinases), protein kinases (AKT), and translation initiation complexes (EIFs) to mTOR has been extensively modeled, but does not fully describe mTOR system behavior. Here, we use quantitative multiplex coimmunoprecipitation to monitor a protein interaction network (PIN) composed of 300+ binary interactions among mTOR-related proteins. Using a simple model system of serum-deprived or fresh-media-fed mouse 3T3 fibroblasts, we observed extensive PIN remodeling involving 27+ individual protein interactions after 1 h, despite phosphorylation changes observed after only 5 min. Using small molecule inhibitors of phosphoinositide 3-kinase, AKT, mTOR, MEK and ERK, we define subsets of the PIN, termed “modules”, that respond differently to each inhibitor. Using primary fibroblasts from individuals with overgrowth disorders caused by pathogenic PIK3CA or MTOR variants, we find that hyperactivation of mTOR pathway components is reflected in a hyperactive PIN. Our data define a “modular” organization of the mTOR PIN in which coordinated groups of interactions respond to the activation or inhibition of distinct nodes, and demonstrate that kinase inhibitors affect the modular network architecture in a complex manner, inconsistent with simple linear models of signal transduction.